1. Field of the Invention
This invention relates generally to arc welding and more specifically to a contact tube improvement to reduce the degree of electrical erosion.
2. Description of the Related Art
Arc welding processes such as gas metal arc welding (GMAW), flux cored arc welding (FCAW) and submerged arc welding (SAW) use continuously-fed consumable electrodes. These electrodes are guided through and maintain contact with a contact tube which also acts to transfer current to the electrode. Because of their function in transferring current, the tubes must have high conductivity and therefore are generally manufactured from copper alloys. Contact tubes are considered an expendable component which must be periodically replaced as a result of abrasive wear and electrical erosion which cause deterioration of the tubes. Because of this deterioration, the welding industry has long sought various means for increasing the useful life of the contact tubes. Although electrical erosion has been identified in the art as a source of deterioration, applicant is unaware of related art identifying the underlying cause of this phenomenon.